Mechanical interlock for catheters

ABSTRACT

An intravascular device delivery system has an elongated member with a flexible hypotube. The hypotube can be rotationally keyed to a steerable catheter. The flexible hypotube includes one or more cuts to allow bending of the flexible hypotube within a first plane. The steerable catheter is steerable to bend the flexible hypotube within the first plane, and longitudinally movable relative to the flexible hypotube to allow distal movement of the steerable catheter relative to a distal end of the flexible hypotube.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.15/662,076, filed Jul. 27, 2017, which claims benefit of and priority toU.S. Provisional Patent Application No. 62/368,711, filed Jul. 29, 2016and titled “Hypotube Reinforced Intravascular Device Delivery Systemsand Methods”, U.S. Provisional Patent Application No. 62/380,246, filedAug. 26, 2016 and titled “Rotational Fixation of Catheters”, U.S.Provisional Patent Application No. 62/436,887, filed Dec. 20, 2016 andtitled “Mechanical Interlock for of Catheters”, U.S. Provisional PatentApplication No. 62/462,776, filed Feb. 23, 2017 and titled “Systems andMethods for Loading and Deploying an Intravascular Device,” thedisclosures of which are incorporated herein by references in theirentireties.

BACKGROUND OF THE DISCLOSURE

Intravascular medical procedures allow the performance of therapeutictreatments in a variety of locations within a patient's body whilerequiring only relatively small access incisions. An intravascularprocedure may, for example, eliminate the need for open-heart surgery,reducing risks, costs, and time associated with an open-heart procedure.The intravascular procedure also enables faster recovery times withlower associated costs and risks of complication. An example of anintravascular procedure that significantly reduces procedure andrecovery time and cost over conventional open surgery is a heart valvereplacement or repair procedure. An artificial valve is guided to theheart through the patient's vasculature. For example, a catheter isinserted into the patient's vasculature and directed to the inferiorvena cava. The catheter is then urged through the inferior vena cavatoward the heart by applying force longitudinally to the catheter. Uponentering the heart from the inferior vena cava, the catheter enters theright atrium. The distal end of the catheter may be deflected by one ormore wires positioned inside the catheter. Precise control of the distalend of the catheter allows for more reliable and faster positioning of amedical device and/or implant and other improvements in the procedures.

The devices can also be directed through the valve chordae or papillarymuscles, for example, for interventional therapy to the mitral valve.When such procedures require the use of more than one instrument, eachinstrument would be dependent upon proper positioning in relation to thevalve. Therefore, positioning or steering mechanisms need to be builtinto each instrument. This adds further cost, complexity, and time tothe procedures.

Other procedures may include tracking a catheter and/or access sheathfrom a puncture in the femoral vein through the intra-atrial septum tothe left atrium. This pathway may be used to access the left atrium forablation of the atrium wall or ablation around the pulmonary veins. Suchinterventional therapies would require precise alignment with targetareas for proper ablation placement. Additionally, alternative accessroutes and/or access routes to other cavities may be desired.

In particular, a smaller thickness of the elongated portion of theintravascular device delivery system allows access routes to be usedthat may have previously been too small in diameter and/or reduce thelikelihood of trauma in conventional access routes through the patient'svasculature. A smaller thickness of the elongated portion also reducesthe force necessary to move the delivery system to the target location.A smaller thickness of the elongated portion also allows more robuststeering mechanisms to be used to direct or steer the catheter and/oraccess sheath to the target location.

BRIEF SUMMARY OF THE DISCLOSURE

In an embodiment, an intravascular device delivery system includes anelongated member. The elongated member includes at least one steerablecatheter and a flexible hypotube positioned radially outside andcircumferentially about the at least one steerable catheter. The atleast one steerable catheter has a proximal end, a distal end, and alongitudinal axis extending therebetween. The flexible hypotube iscoaxial with the at least one steerable catheter and has at least oneslit cut and may have an additional island cuts out to directflexibility of the flexible hypotube. The flexible hypotube and the atleast one steerable catheter are rotationally fixed to one another at afirst key assembly.

In another embodiment, an intravascular device delivery system includesa handle and an elongated member operably coupled to the handle. Theelongated member includes at least one steerable catheter and a flexiblehypotube positioned radially outside and circumferentially about thesteerable catheter. The at least one steerable catheter has a proximalend, a distal end, and a longitudinal axis extending therebetween. Theflexible hypotube is coaxial with the at least one steerable catheterand has at least one island cut and at least one slit cut to directflexibility of the flexible hypotube. The flexible hypotube and the atleast one steerable catheter are rotationally fixed to one another at afirst key assembly. The handle has one or more controls thereon to movethe at least one steerable catheter longitudinally relative to theflexible hypotube.

In yet another embodiment, a method for delivering an intravasculardevice includes steering a steerable catheter in a first plane, thesteerable catheter being positioned radially inside a flexible hypotube;and bending the flexible hypotube in the first plane to create a firstbend in the flexible hypotube. The method also includes advancing thesteerable catheter distally relative to the flexible hypotube and distalof a distal end of the flexible hypotube, steering the steerablecatheter in a second plane, and positioning a distal end of thesteerable catheter at a target location.

In yet another embodiment, an intravascular device delivery systemincludes a catheter having a flexible hypotube including a firsthypotube of a first stiffness and a second hypotube of a secondstiffness. The first hypotube and the second hypotube are joinedtogether through a mechanical interlock. The first and second hypotubesbeing covered with an outer sheath.

In yet another embodiment, an intravascular delivery device systemincludes a catheter including a first hypotube having a first stiffnessportion and a second stiffness portion that is stiffer than the firststiffness portion. A stiffening member is disposed within a portion ofthe catheter and is movable relative to the first stiffness portion andthe second stiffness portion. Movement of the stiffening member from thefirst stiffness portion to the second stiffness portion changes theflexibility of the first stiffness portion to allow enhancedflexibility.

This summary is provided to introduce a selection of concepts that arefurther described below in the detailed description. This summary is notintended to identify specific features of the claimed subject matter,nor is it intended to be used as an aid in limiting the scope of theclaimed subject matter.

Additional features of embodiments of the disclosure will be set forthin the description which follows. The features of such embodiments maybe realized by means of the instruments and combinations particularlypointed out in the appended claims. These and other features will becomemore fully apparent from the following description and appended claims,or may be learned by the practice of such exemplary embodiments as setforth hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to describe the manner in which the above-recited and otherfeatures of the disclosure can be obtained, a more particulardescription will be rendered by reference to specific embodimentsthereof which are illustrated in the appended drawings. For betterunderstanding, the like elements have been designated by like referencenumbers throughout the various accompanying figures. While some of thedrawings may be schematic or exaggerated representations of concepts, atleast some of the drawings may be drawn to scale. Understanding that thedrawings depict some example embodiments, the embodiments will bedescribed and explained with additional specificity and detail throughthe use of the accompanying drawings in which:

FIG. 1 is a schematic representation of an embodiment of anintravascular device delivery system, according to the presentdisclosure;

FIG. 2 is a side partial cutaway view illustrating an embodiment of theelements of the elongated member of FIG. 1, according to the presentdisclosure;

FIG. 3 is a perspective view of the embodiment of an elongated member ofFIG. 2 traversing the compound bends used to access the mitral valve ofthe heart, according to the present disclosure;

FIG. 4A is a plan view of an embodiment of a cut pattern in a flexiblehypotube, according to the present disclosure;

FIG. 4B is a side schematic view of an embodiment of a flexible hypotubewith island cuts of varying sizes, according to the present disclosure;

FIG. 5A is a schematic representation of the embodiment of anintravascular device delivery system of FIG. 1 showing a keyed hypotube,according to the present disclosure;

FIG. 5B is a cross-sectional view of an embodiment of a steerablecatheter with a tab keyed to the flexible hypotube, according to thepresent disclosure;

FIG. 5C is a cross-sectional view of another embodiment of a steerablecatheter with a tab keyed to a flexible hypotube, according to thepresent disclosure;

FIG. 6 is a flowchart illustrating a method of delivering anintravascular device, according to the present disclosure;

FIG. 7 is a side cross-sectional view of an embodiment of an activelydeflectable flexible hypotube, according to the present disclosure;

FIG. 8 is a plan view of an embodiment of a cut pattern in a flexiblehypotube, according to the present disclosure;

FIG. 9 is a plan view of an embodiment of a mechanical interlock formedin the flexible hypotube, according to the present disclosure; and

FIG. 10 is a cross-sectional view of another embodiment of intravasculardevice delivery system, according to the present disclosure.

FIG. 11 is a partial cross-sectional view of another embodiment of anintravascular device delivery system, according to the presentdisclosure.

FIG. 12 is a cross-sectional view of the intravascular device deliverysystem of FIG. 11, according to the present disclosure.

FIGS. 13A and 13B are side views of the intravascular device deliverysystem of FIG. 11, according to the present disclosure

FIG. 14 is a cross-sectional view of a stiffening member, according tothe present disclosure.

DETAILED DESCRIPTION

One or more specific embodiments of the present disclosure will bedescribed below. In an effort to provide a concise description of theseembodiments, some features of an actual embodiment may be described inthe specification. It should be appreciated that in the development ofany such actual embodiment, as in any engineering or design project,numerous embodiment-specific decisions will be made to achieve thedevelopers' specific goals, such as compliance with system-related andbusiness-related constraints, which may vary from one embodiment toanother. It should further be appreciated that such a development effortmight be complex and time consuming, but would nevertheless be a routineundertaking of design, fabrication, and manufacture for those ofordinary skill having the benefit of this disclosure.

One or more embodiments of the present disclosure may generally relateto manufacturing and using intravascular device delivery systems orother steerable intravascular system. An intravascular device deliverysystem may allow a medical professional to deliver an intravascular orother medical device to a target location in a patient's body. While thepresent disclosure will describe intravascular device delivery systemsand applications thereof in relation to intravascular procedures in theheart, it should be understood that the devices, systems, and methodsdescribed herein may be applicable to other bodily lumens and/orcavities. Additionally, elements described in relation to any embodimentdepicted and/or described herein may be combinable with elementsdescribed in relation to any other embodiment depicted and/or describedherein. For example, and not by way of limitation to any othercombinations of embodiments, any element described in relation to anembodiment depicted in FIG. 2 may be combinable with any element of anembodiment described in FIG. 4, and any element described in relation toan embodiment described in FIG. 5 may be combinable with any element ofan embodiment depicted in FIG. 3, any element described in relation toan embodiment described in FIG. 10 may be combinable with any element ofan embodiment depicted in FIG. 7, any element described in relation toan embodiment described in FIGS. 8-9 may be combinable with any elementof an embodiment depicted in FIGS. 2-7 and 10, and any element describedin relation to an embodiment described in FIGS. 11-14 may be combinablewith any elements of an embodiment depicted in FIGS. 2-10.

An intravascular device delivery system may include a flexible elongatedmember that has a distal end and a proximal end. A handle may beconnected to a proximal end of the elongated member to allow a user,such as a medical professional and/or clinician, to control one or moremovements of the elongated member. An intravascular device may bepositioned at and/or connected to the distal end of the elongatedmember.

In some embodiments, the elongated member may include a plurality ofelements. For example, the elongated member may include a plurality ofelements that extend from the proximal end to the distal end. In someembodiments, at least one of the elements of the elongated member mayinclude a plurality of lumens therethrough to allow steerability of theelement. In at least one embodiment, at least one element of theelongated member may be steerable in at least two planes.

In some embodiments, the handle may include one or more controls (e.g.,a knob, a button, a lever, or other controls) that may move at least onepart of the intravascular device delivery system relative to another.For example, the handle may include one or more controls for moving atleast one element of the elongated member relative to another element ofthe elongated member. The handle may move an inner element relative toan outer element of the elongated member in a proximal direction, in adistal direction, in a rotational direction, or combinations thereof.

FIG. 1 illustrates a schematic representation of an intravascular devicedelivery system 100. The system 100 may include an elongated member 102having a proximal end 104 and a distal end 106. A handle 108 may beconnected to the proximal end 104 of the elongated member 102. Anintravascular device 110 may be positioned at and/or connected to thedistal end 106.

The elongated member 102 may be flexible, allowing the elongated member102 to traverse a patient's tortuous vasculature or other anatomy. Insome embodiments, the elongated member 102 may deliver the intravasculardevice 110 to a target location in the patient's body, such asdelivering a filter, scaffold, stent, body tissue repair device, heartvalve, or other implantable devices. In other embodiments, the system100 and elongated member 102 may be provided without an intravasculardevice 110 at the distal end 106 such that the system may recapture,reposition, or otherwise move an intravascular device previouslypositioned in the patient's body.

The elongated member 102 of the system 100 may include one or moreelements therein. An element of the elongated member 102 may include acatheter, a guidewire, a sheath, a drive cable, other tubular and/orsolid element, or combinations thereof. In some embodiments an elementof the elongated member 102 may extend an entire length of the elongatedmember 102 from a proximal end 104 to a distal end 106 of the elongatedmember 102. In other embodiments, an element of the elongated member 102may have a length less than the entire length of the elongated member102. For example, an element may provide support to the elongated member102 from the proximal end 104 toward the distal end 106 withoutcontinuing the entire length to the distal end 106.

FIG. 2 is a side partial cutaway view of part of an embodiment of theelongated member 102 of the intravascular device delivery system 100 ofFIG. 1. In some embodiments, the elongated member 102 may include anouter sleeve 112, a flexible hypotube 114, a steerable catheter 116, andan inner catheter 118. In some embodiment, the inner element may be aninner catheter. In other embodiments, the inner element 118 may be aguidewire or other guide element to assist in directing the elongatedmember 102 through tortuous anatomy. In some embodiments, the flexiblehypotube may be a lasercut hypotube, a hydrocut hypotube, a hypotubewith one or more cuts therein by other cutting methods, such as EDM ormechanical cutting, or a 3D printed hypotube with one or more openingstherein.

The elongated member 102 has a longitudinal axis 126 that extends fromthe proximal end (i.e., proximal end 104 in FIG. 1) to the distal end(i.e., distal end 106 in FIG. 1) of the elongated member 102. In someembodiments, all of the elements of the elongated member 102 may extenda full length of the elongated member 102. In other embodiments, atleast one of the elements may have a length that is less than the fulllength of the elongated member 102. For example, the flexible hypotube114 may have a length that is less than the full length of the elongatedmember 102. In other examples, the outer sleeve 112 may have a lengthless than the full length of the elongated member 102. In at least oneexample, the flexible hypotube 114 may have a length that is less than alength of the steerable catheter 116.

In some embodiments, the flexible hypotube 114 may have a wall thicknessthat is less than the thickness of a conventional steerable catheter.For example, the flexible hypotube 114 may have a wall thickness that isa percentage of a wall thickness of the steerable catheter 116 in arange having upper value, a lower value, or upper and lower valuesincluding any of 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 60%, 70%,80%, 90% or any values therebetween. For example, the wall thickness ofthe flexible hypotube 114 may be less than 90% of the wall thickness ofthe steerable catheter 116. In other examples, the wall thickness of theflexible hypotube 114 may be between 10% and 90% of the wall thicknessof the steerable catheter 116. In yet other examples, the wall thicknessof the flexible hypotube 114 may be between 15% and 50% of the wallthickness of the steerable catheter 116. In at least one embodiment, thewall thickness of the flexible hypotube 114 may be about 20% of the wallthickness of the steerable catheter 116.

FIG. 3 illustrates an example of a series of compound bends that theelongated member 102 may perform during the delivery, repair, recapture,repositioning, or other interaction with an intravascular device at amitral valve in a patient's heart. While embodiments of an intravasculardevice and intravascular device delivery system are described herein inrelation to mitral valve repair, it should be understood thatembodiments of the present disclosure may be used in other intravascularprocedures, such as septal repair, transapical procedures, transeptalprocedures, transarterial procedures, other coronary procedures, otherintravascular procedures, or other intraluminal medical procedures.

While accessing a mitral valve or other intravascular procedure havingat least one bend in a bodily cavity, the elongated member 102 may besteered by the steerable catheter 116. The steerable catheter 116 may beany suitable steerable catheter 116 known in the art. In someembodiments, the steerable catheter 116 may be steerable in at least oneplane of motion. In another embodiment, the steerable catheter 116 maybe steerable in at least two planes of motion. In at least oneembodiment, the steerable catheter 116 is steerable in two planes ofmotion substantially perpendicular to one another.

In the depicted embodiment, the elongated member 102 is shown with onlythe flexible hypotube 114 and the steerable catheter 116 for clarity.The steerable catheter 116 may extend distally at least partially from adistal end of the flexible hypotube 114. The elongated member 102 has afirst bend 120 in which both the flexible hypotube 114 and the steerablecatheter 116 deflect. The first bend 120 may have a first bend angle 124measured between a first longitudinal axis 126-1 proximal of the firstbend 120 to a second longitudinal axis 126-2 distal the first bend 120.In some embodiments, the first bend angle 124 may be in a range havingan upper value, a lower value, or an upper and lower value including anyof 60°, 65°, 70°, 75°, 80°, 85°, 90°, 95°, 100°, 105°, 110°, 115°, 120°,125°, 130°, 135°, 140°, 145°, 150°, 155°, 160°, 165°, 170°, 175°, or anyvalues therebetween. For example, the first bend angle 124 may begreater than 60°. In other example, the first bend angle 124 may be lessthan 175°. In yet other examples, the first bend angle 124 may be in arange of 60° to 175°. In further examples, the first bend angle 124 maybe in a range of 90° to 120°. In at least one example, the first bendangle 124 may be about 105°.

The elongated member 102 has a second bend 128 in which the steerablecatheter 116 is deflected with a compound angle relative to the firstlongitudinal axis 126-1. The second bend 128 has a second bend angle 130between a third longitudinal axis 126-3 distal of the second bend 128relative to the second longitudinal axis 126-2 proximal the second bend128. The second bend 128 may also have a rotational angle 132 relativeto a plane in which the first longitudinal axis 126-1 and the secondlongitudinal axis 126-2 lie. In other words, the rotational angle 132 isrelative to the amount of rotation of the third longitudinal axis 126-3relative to the direction of the first bend 120.

In some embodiments, the second bend angle 130 may be in a range havingan upper value, a lower value, or an upper and lower value including anyof 60°, 65°, 70°, 75°, 80°, 85°, 90°, 95°, 100°, 105°, 110°, 115°, 120°,125°, 130°, 135°, 140°, 145°, 150°, 155°, 160°, 165°, 170°, 175°, or anyvalues therebetween. For example, the second bend angle 130 may begreater than 60°. In other example, the second bend angle 130 may beless than 175°. In yet other examples, the second bend angle 130 may bein a range of 60° to 175°. In further examples, the second bend angle130 may be in a range of 80° to 110°. In at least one example, thesecond bend angle 130 may be about 90°.

In some embodiments, the rotational angle 132 of the third longitudinalaxis 126-3 (i.e., a distal end of the steerable catheter 116) relativeto the first longitudinal axis 126-1 may be in a range having an uppervalue, a lower value, or an upper and lower value including any of 30°,35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, 85°, 90°, 100°, 110°,120°, 130°, 140°, 150°, 160°, or any values therebetween. For example,the rotational angle 132 may be greater than 30°. In other example, therotational angle 132 may be less than 160°. In yet other examples, therotational angle 132 may be in a range of 30° to 160°. In furtherexamples, the rotational angle 132 may be in a range of 45° to 135°. Inat least one example, the second bend angle 130 may be about 60°.

In order to allow the flexible hypotube 114 to bend with the steerablecatheter 116, one or more cuts may be made in through a wall of theflexible hypotube 114. FIG. 4A illustrates a flat view of a cut patternfor a flexible hypotube 114 according to the present disclosure. Theflat view illustrates the pattern of the cuts as though a cylindricalhypotube were laid flat. In other words, the top edge of the cut patternand the bottom edge of the cut pattern are connected and continuous inthe flexible hypotube 114 such that the slits 134 and island cuts 136are oriented circumferential and spaced apart by the spinestherebetween. The cut pattern may include at least one slit 134 and atleast one island cut 136. As shown in FIG. 4A, the cut pattern may havea plurality of slits 134 and/or a plurality of island cuts 136.

The slit 134 may transmit longitudinal force along the flexible hypotube114 and allow expansion of the flexible hypotube 114 when the flexiblehypotube 114 is deflected in a direction opposite the slit 134. Theisland cuts 136 may allow compression of the flexible hypotube 114 whenthe flexible hypotube 114 is deflected in a direction of the island cuts136. For example, slits 134 and island cuts 136 located rotationallyopposite one another on a flexible hypotube 114 may direct preferentialbending of the hypotube along a center line 138 of the island cuts 136.For example, a flexible hypotube 114 with the cut pattern of FIG. 4A maypreferentially bend along the center line 138 within a bend regiondefined by the cut pattern.

While the island cuts 136 are depicted in FIG. 4A as diamond-shaped, theisland cuts 136 may have one or more other shapes, such as square,rhombohedral, triangular, rectangular, circular, oblong, otherelliptical, other polygonal, irregular, or combinations thereof.

FIG. 4B is a side view of a flexible hypotube 214 having a plurality ofisland cuts 236 therein which may vary in size along a longitudinallength of the flexible hypotube 214. For example, a first island cut236-1 may be shorter in the longitudinal direction than a second islandcut 236-2 in a different longitudinal portion of the flexible hypotube214. In at least one embodiment, the island cuts increase inlongitudinal length in a distal direction. In another example, a thirdisland cut 236-3 may be narrower in the rotational direction about theflexible hypotube 214 than the second island cut 236-2 in a differentlongitudinal portion of the flexible hypotube 214. In at least oneembodiment, the island cuts become wider in the rotation direction in adistal direction. The flexible hypotube 214 may have one or more slitsopposite the island cuts 236 (not visible in FIG. 4B).

FIG. 5A illustrates the preferential bending of the flexible hypotube114 in the intravascular device delivery system 100. Only the flexiblehypotube 114 and steerable catheter 116 of the elongated member areshown in FIG. 5 for clarity and to show the relative motion of theflexible hypotube 114 and steerable catheter 116.

The flexible hypotube 114 has a bend region 146 containing one or moreslits 134 and island cuts 136. The steerable catheter 116 may apply atransverse force to the flexible hypotube 114 to bend the bend region146. As shown in FIG. 5, the slits 134 may open (i.e., expand) and theisland cuts 136 may close (i.e., compress) to allow the bend region 146to bend at the first bend 120. The orientation of the first bend 120(i.e. rotational orientation about a longitudinal axis) may becontrolled by rotation of the steerable catheter 116 and flexiblehypotube 114 together.

The flexible hypotube 114 and steerable catheter 116 may be rotationallyfixed relative to one another in one or more key assemblies. In theembodiment shown in FIG. 5A, the flexible hypotube 114 and steerablecatheter 116 are rotationally fixed relative to one another by a firstkey assembly 140 and a second key assembly 142. In other embodiments,the flexible hypotube 114 and the steerable catheter 116 may berotationally fixed relative to one another by one key assembly. In yetother embodiments, the flexible hypotube 114 and the steerable catheter116 may be rotationally fixed relative to one another by three or morekey assemblies positioned longitudinally along the flexible hypotube 114and the steerable catheter 116. In further embodiments, the flexiblehypotube 114 and steerable catheter 116 may be rotationally fixedrelative to one another by a first key assembly 140 that extends anentire longitudinal length of the flexible hypotube 114 or steerablecatheter 116.

The first key assembly 140 may rotationally fix the flexible hypotube114 and the steerable catheter 116 by a mechanical interlock of one ormore elements between the flexible hypotube 114 and the steerablecatheter 116. For example, the flexible hypotube 114 includes a firstslot 148 and a second slot 150. The first slot 148 and the second slot150 are configured to receive a first tab 152 and a second tab 154 ofthe steerable catheter 116, such that the first tab 152 engages with thefirst slot 148 to form the first key assembly 140 and the second tab 154engages with the second slot 150 to form the second key assembly 142. Inother embodiments, the mechanical interlock may have other forms. Forexample, the first slot 148 may be located in the steerable catheter 116and the first tab 152 may be fixed relative to the flexible hypotube. Inother examples, such as a first key assembly 140 that extends an entirelongitudinal length of the flexible hypotube 114 or steerable catheter116, the first slot 148 may extend substantially or the entirelongitudinal length of the flexible hypotube 114 or steerable catheter116 and a plurality of tabs (e.g., first tab 152 and second tab 154) mayengage with the first slot 148.

In some embodiments, the first tab 152 and/or second tab 154 may beintegrally formed with the steerable catheter 116. However, anintegrally formed first tab 152 and/or second tab 154 may introducechallenges during assembly of the device. In other embodiments, a firsttab 152 and/or second tab 154 may be connected to the steerable catheter116 through the first slot 148 and/or second slot 150, respectively,after the steerable catheter 116 is positioned radially within theflexible hypotube 114. For example, a first tab 152 and/or second tab154 may be connected to an outer surface of the steerable catheter 116by sonic welding, thermal welding, an adhesive, a clip, a pin, a rivet,a screw, another mechanical fastener, or a combination thereof.

FIG. 5B is a longitudinal cross-sectional of an embodiment of asteerable catheter 216 with a tab 252. The steerable catheter 216 has abody 253. The body 253 includes a lumen 255 contained within a wall ofthe body 253 that extends along a least a portion of the longitudinallength of the steerable catheter 216. One or more cuts 257 are made inthe outer surface of the body 253 through to the lumen 255. A tab 252 isinserted into the one or more cuts 257 to retain the tab 252 in the body253 of the steerable catheter 216 with at least a portion of the tab 252extending radially from the body 253, as shown in FIG. 5B. The tab 252may include or be made of spring steel, shape memory material likeNitinol, other steel alloys, aluminum, titanium, an organic polymer, aninorganic polymer, other materials, or combinations thereof. In someembodiments, the tab 252 is held in the lumen 255 with an adhesive.

In other embodiments, the tab 252 is placed in the steerable catheter216 before positioning the steerable catheter 216 in the flexiblehypotube. In such embodiments, the tab 252 is held in the lumen 255 withan adhesive at only one end of the tab 252, allowing the other end tomove freely. The free end allows the tab to collapse radially duringpositioning of the steerable catheter 216 in the flexible hypotube.

As shown in FIG. 5C, in other embodiments of a steerable catheter 316,the tab 352 may have other shapes than shown in FIG. 5B. For example,the tab 352 may have discontinuous corners, such as 90° corners. Inother embodiments, the tab 352 may have a mix of curved surfaces anddiscontinuous corners to facilitate assembly of the tab 352 into thebody 353 of the steerable catheter 316 through the slot 350 of theflexible hypotube 314 while allowing for 1:1 torque transmission betweenthe steerable catheter 316 and the flexible hypotube 314.

Referring again to FIG. 5A, the first key assembly 140 rotationally keysthe flexible hypotube to the steerable catheter 116 by limiting and/orpreventing movement of the first tab 152 rotationally relative to thefirst slot 148. The second key assembly 142 rotationally keys theflexible hypotube 114 to the steerable catheter 116 at a location distalof the first key assembly 140 by limiting and/or preventing movement ofthe second tab 154 rotationally relative to the second slot 150. Thefirst slot 148 has a first slot length 156 in a longitudinal direction.The first tab 152 may move longitudinally within the first slot 148,allowing at least a portion of the steerable catheter 116 to translatelongitudinally relative to the flexible hypotube 114 while the steerablecatheter 116 is rotationally keyed to the flexible hypotube 114. Thesecond tab 154 may move longitudinally within the second slot 150,allowing at least another portion of the steerable catheter 116 (distalof the first key assembly 140) to translate longitudinally relative tothe flexible hypotube 114.

Longitudinal translation of the steerable catheter 116 relative to theflexible hypotube 114 allows the steerable catheter 116 to bend the bendregion 146 of the flexible hypotube 114 at the first bend 120, and thentranslate longitudinally in a distal direction and project from theflexible hypotube 114 (i.e., extend beyond a distal end of the flexiblehypotube 114). For example, the steerable catheter 116 may bend theflexible hypotube 114 at the bend region 146 in a first direction andmove distally through the flexible hypotube 114 beyond the distal end ofthe flexible hypotube 114. The steerable catheter 116 may then besteered in a second direction by one or more controls on the handle 108.The amount of longitudinally displacement of the steerable catheter 116relative to the flexible hypotube 114 may be at least partiallydetermined by the first slot length 156 and/or the second slot length158.

In some embodiments, the first slot length 156 may be equivalent to thesecond slot length 158. In other embodiments, the first slot length 156may be greater than the second slot length 158. In yet otherembodiments, the first slot length 156 may be less than the second slotlength 158. In some embodiments, the first slot length 156 and/or thesecond slot length 158 may be in a range including an upper value, alower value, or upper and lower values including any of 2.0 centimeters,2.5 centimeters, 3.0 centimeters, 3.5 centimeters, 4.0 centimeters, 4.5centimeters, 5.0 centimeters, 5.5 centimeters, 6.0 centimeters, 6.5centimeters, 7.0 centimeters, 7.5 centimeters, 8.0 centimeters, 8.5centimeters, 9.0 centimeters, 9.5 centimeters, 10.0 centimeters, or anyvalues therebetween. For example, the first slot length 156 and/or thesecond slot length 158 may be greater than 2.0 centimeters. In anotherexample, the first slot length 156 and/or the second slot length 158 maybe less than 10.0 centimeters. In yet other examples, the first slotlength 156 and/or the second slot length 158 may be between 2.0centimeters and 5.0 centimeters. In further examples, the first slotlength 156 and/or the second slot length 158 may be in a range of 2.5centimeters to 4.5 centimeters. In at least one embodiment, the firstslot length 156 and/or the second slot length 158 may be about 3.0centimeters.

The first slot 148 and the second slot 150 are rotationally aligned withone another in the embodiment of FIG. 5A. In other embodiments, thefirst slot 148 and second slot 150 may be rotationally displaced fromone another. For example, the first slot 148 may be on a first side ofthe flexible hypotube 114 and the second slot 150 may be displaced at anangular amount from the first slot 148, such as 180° to angularly opposethe first slot 148. In other examples, the first slot 148 and secondslot 150 may be rotationally displaced from one another by another anglebetween 0° and 180°.

In some embodiments the first slot length 156 and/or second slot length158 may limit the amount the steerable catheter 116 may extend distallyof a distal end of the flexible hypotube 114. For example, the amountthe steerable catheter 116 may extend distally of a distal end of theflexible hypotube 114 may be in a range including an upper value, alower value, or upper and lower values including any of 2.0 centimeters,2.5 centimeters, 3.0 centimeters, 3.5 centimeters, 4.0 centimeters, 4.5centimeters, 5.0 centimeters, 5.5 centimeters, 6.0 centimeters, 6.5centimeters, 7.0 centimeters, 7.5 centimeters, 8.0 centimeters, 8.5centimeters, 9.0 centimeters, 9.5 centimeters, 10.0 centimeters or anyvalues therebetween. For example, the amount the steerable catheter 116may extend distally of a distal end of the flexible hypotube 114 may begreater than 2.0 centimeters. In another example, the amount thesteerable catheter 116 may extend distally of a distal end of theflexible hypotube 114 may be less than 10.0 centimeters. In yet otherexamples, the amount the steerable catheter 116 may extend distally of adistal end of the flexible hypotube 114 may be between 2.0 centimetersand 10.0 centimeters. In further examples, the amount the steerablecatheter 116 may extend distally of a distal end of the flexiblehypotube 114 may be in a range of 2.5 centimeters to 6.5 centimeters. Inat least one embodiment, the amount the steerable catheter 116 mayextend distally of a distal end of the flexible hypotube 114 may beabout 3.0 centimeters.

Upon extending the steerable catheter 116 distally of the flexiblehypotube 114, the steerable catheter 116 may be steered about the secondbend 128, as described in relation to FIG. 3, and an intravasculardevice 110 may be deployed distally from the steerable catheter 116. Insome embodiments, the intravascular device 110 may be deployed byactivating one or more portions of the intravascular device 110 (such aswings, clips, extensions, needles, etc.). In other embodiments, theintravascular device 110 may be deployed by moving the intravasculardevice 110 longitudinally relative to a sleeve or sheath constraining aradial expansion of the intravascular device 110 (such as with aself-expanding stent or other self-expanding intravascular device 110).

FIG. 6 illustrates a method 260 for delivering an intravascular device.The method 260 includes steering 262 a portion of an elongated member.For example, steering 262 the portion of the elongated member mayinclude using a steerable catheter to steer a distal end of theelongated member. In other examples, steering 262 the portion of theelongated member may include steering the portion of the elongatedmember in a bodily cavity. The steering 262 may be performed using oneor more cables, wires, sutures, or other force transmission mechanismsto transmit force from a handle to the portion of the elongated memberto be deflected. In some embodiments, the elongated member may have onesteerable catheter. In other embodiments, the elongated member may havea plurality of steerable catheters. For example, the elongated membermay have a steerable catheter that is steerable in at least two planes.In other examples, the elongated member may have a first steerablecatheter that is steerable in a first plane and a second steerablecatheter that is steerable in a second plane.

The method 260 includes bending 264 a bend region of a flexiblehypotube. In some embodiments, the flexible hypotube may preferentiallybend in plane. In other embodiments, the flexible hypotube maypreferentially bend in a particular direction within a plane, relativeto a longitudinal axis of the elongated member. The flexible hypotubemay have a plurality of cuts, such as island cuts and/or slits, in thebody of the flexible hypotube to direct bending of the flexiblehypotube. After bending 264 the flexible hypotube, the method 260includes advancing 266 at least a portion of the steerable catheter (orcatheters) in a distal direction. In some embodiments, the steerablecatheter may follow the bend of the flexible hypotube, and a steerableportion of the steerable catheter may be positioned distally beyond adistal end of the flexible hypotube.

The method 260 includes steering 268 a portion of the steerable catheteradvanced distally beyond the flexible hypotube. In some embodiments,steering the portion of the steerable catheter that is advanced distallybeyond the flexible hypotube includes steering the steerable catheter ina second plane that is non-coplanar from the first plane in which theflexible hypotube bends. For example, steering 268 the steerablecatheter after advancing 266 the steerable catheter allows for thecompound bend shown in FIG. 3.

Referring again to FIG. 6, the method 260 further includes positioningthe distal end of the steerable catheter at or adjacent to a targetlocation. In some embodiments, the target location may be a deliverylocation for an intravascular device. In other embodiments, the targetlocation may be a repositioning location for a partially deployedintravascular device. In other embodiments, the target location may bean opening to be close by an intravascular device.

In at least one embodiment, a flexible hypotube can be activelydeflected. As shown in FIG. 7, an intravascular device delivery systemaccording to the present disclosure may include a flexible hypotube 314that is embedded in a catheter body 370. The catheter body 370 includesat least one lumen 372 through which a tension or steering cable 374 isconnected to an end ring 376 welded to the flexible hypotube 314. Theproximal ends of the tension cable 374 are attached to a handle to allowthe flexible hypotube 314 to deflect when tension force is applied tothe tension cable 374.

In some embodiments, an intravascular device delivery system accordingto the present disclosure may allow delivery of larger intravasculardevices and/or through smaller bodily conduits. The intravascular devicedelivery system may allow for new and/or improved procedures with lessrisk to the patient and greater ease of operation to the medicalprofessional.

Referring now to FIG. 8 illustrated is a flat view of another cutpattern for a flexible hypotube or catheter according to the presentdisclosure. The flat view illustrates the pattern of the cuts as thougha cylindrical hypotube, for example, were laid flat. In other words, thetop edge of the cut pattern and the bottom edge of the cut pattern areconnected and continuous in the flexible hypotube, such that the slitsand island cuts are oriented circumferential and spaced apart by thespines therebetween. This particular cut pattern allows the flexiblehypotube to bend in 2 different planes, while providing desired 1:1torque control and flexibility. Those planes can be at various angularorientations relative to each other, such as perpendicular ornon-perpendicular planes.

As mentioned before, a location of the spine and the design of the slitsand cuts define how the hypotube deflects during steering of theintravascular device delivery system. The flexible area of the flexiblehypotube, i.e., those areas with the slits and/or cuts, can have variouslengths and the slits and cuts of FIGS. 8 and 9 can be the same as otherslits and cuts described herein.

As illustrated in FIG. 8, one hypotube 400 can include various sectionswith and without flexibility patterns or cut patterns based upon theparticular movement from the hypotube 400. For instance, some ofsections I-X are stiffer than other sections to aid with steering theintravascular device delivery system. As shown, section I includes anumber of holes 402, however, a remainder of that section has no cuts orslits. The holes 402 can have a diameter of about 0.5 mm and there canbe about 9 holes disposed about the circumference of Section I. Otherdiameters and number of holes are also possible. For instance, thediameter of the holes 402 can be from about 0.3 mm to about 1 mm. Inaddition, the number of holes can be greater than or less than 9. Forinstance, the number of holes can be about 3 to about 12.

Sections II-IX have differing number of slits and/or cuts, while sectionX has no cuts or slits. The cuts and islands can vary based upon theselected flexibility and torque of the hypotube 400. For instance, asillustrated in FIG. 8, Section II has 12 cut rings, each ring having awidth of about 5.5 mm, Section III has similar to section II, butrotated 90 degrees, and with 6 ring, each having a width of about 2.5mm, Section IV has 12 rings, each having a width of about 5.5 mm,Section V has 14 rings, each having a width of about 13 mm, Section VIhas similar to section II, but rotated 90 degrees, and with 12 ring,each having a width of about 5.5 mm, Section VII has 30 cut rings, eachring having a width of about 14.5 mm, Section VIII has a similar toSection IV, but rotated 90 degrees, with 12 cut rings, each ring havinga width of about 5.5 mm, Section IX has a similar to Section V with 11cut rings, each ring having a width of about 10 mm

While specific dimension and ring number are provided for hypotube 400,other widths and number of rings are also possible to achieveflexibility and torque transmission for steering through the tortuousanatomy. For instance, in other configurations the number rings can befrom about 1 to about 40, with a width of the rings ranging from about0.5 mm to about 7 mm.

While in many situations the hypotube 400 can be fabricated from asingle material, such as stainless steel or shape memory material, suchas Nitinol, in some circumstances the hypotube 400 can include acombination of materials. For instance, the deformation in Section II-Xmay exceed the plastic deformation ability of a stainless steel. Amaterial much better suited for these Sections II-X could be a shapememory material, such as Nitinol with a plastic deformation limit ofabout 8% compared to stainless steel of <1%. Therefore, in oneconfiguration, different areas or regions of the hypotube 400 can beformed from a material with high deformation limits, such as but notlimited to, Nitinol or some other superelastic, pseudoelastic, or shapemember material.

Because of the high cost of certain superelastic, pseudoelastic, orshape memory material, those sections where high deformation occurscould be formed from Nitinol, while a remainder of the hypotube can beformed from a less expensive material. For instance, the less expensivematerial could be stainless steel 304 or 316. Since these materials aredissimilar, a mechanical interlock in a low stress area can be used tojoin the two different stiffness sections or portions.

To connect the two different sections of the hypotube 400, i.e., ahypotube of a stiffer material and a hypotube of a less stiff material,a mechanical interlock 410 can be used, one example of a mechanicalinterlock 410 being illustrated in FIG. 9. As with FIG. 8, themechanical interlock 410 and associated portions of the hypotube areillustrated in a flat view. The flat view illustrates the pattern of themechanical interlock 410 as though a cylindrical hypotube were laidflat. In other words, the top edge of the mechanical interlock 410 andthe bottom edge of the mechanical interlock 410 are connected andcontinuous in the flexible hypotube. In addition, Section IX and X fromFIG. 8 are illustrated in FIG. 9, with Section IX having a differentconfiguration of 171 rings, and an overall length of that section beingabout 340 mm.

As shown, the mechanical interlock 410 includes a male portion 412 and afemale portion 414. The male portion 412 has at least one finger 420,with an enlarged member 422 disposed at an end thereof. The femaleportion 414 is complementary to the male portion 412 and includes atleast one channel 424 with a receiving space 426 at its end toaccommodate the enlarged member 422. The two portions of the hypotube400 connect together when the finger 420 and enlarged member 422 arereceived in the channel 424 and receiving space 426. For instance, thefinger 420 and the enlarged member 422 can be flexible enough to snapinto the channel 424 and receiving space 426 having a matching shape.

It is understood that the above-described mechanical interlock 400 isnot limited to this specific mechanical interlock described and othermechanical locks can be used as well. For instance, the enlarged member422 can be a ball or have an elongate form, whether or not curved,square, rhombohedral, triangular, rectangular, circular, oblong, otherelliptical, other polygonal, irregular, or combinations thereof.Similarly, the receiving space 426 can accommodate the ball or otherelongate form while being complementary to the enlarged member 422. Thefinger 420 and channel 424 can also have various configurations andorientations.

To aid with securing the two stiffer and less stiff hypotube portions ofthe hypotube 400 together, the hypotube 400 can be covered with an outermember 430, such one or more braids, outer sheaths or other structuresto aid in retaining the finger 420 and the enlarged member 422 in thechannel 424 and the receiving space 426, respectively.

In still another configuration, similar to the embodiment of FIG. 7where the flexible hypotube 314 is embedded in a catheter body 370,instead of incorporating the mechanical interlock into a hypotube thatis disposed over a steerable catheter, the function of the flexiblehypotube and the steerable catheter can be combined into a catheterhaving a single hypotube with channels for tension cables used todeflect the catheter. For instance, and as illustrated in FIG. 10, thehypotube 400, such as a combined Nitinol/Stainless steel laser cuthypotube described in FIGS. 8-9 (or another hypotube fabricated fromanother metal, alloy, or other material), can be covered with tubes 440to create a space for the tension cable (not shown) responsible for thedeflection of the catheter. Those tubes 440 could be polyamide or someother polymer, and could optionally include a polytetrafluoroethylene(PTFE) liner. Alternatively, sacrificial mandrels, which can be removedafter forming the catheter, can be placed on an exterior surface of thehypotube 400, with the tubes 440 or mandrels being placed along the axisof the connected hypotubes 400, i.e., a hypotube of a stiffer materialand a hypotube of a less stiff material.

Covering the tubes 440 or mandrels can be a braid or coil 442, whichhelps position the tubes 440 or mandrels and keep them in place when anouter sheath 444, such as a polymeric jacket, is applied to the braid442 and the tubes 442. The braid or coil 442 limits movement of thetension cable (not shown), i.e., bowing of the tension cable, whenhigh-tension forces are applied during bending and movement of thecatheter.

The outer sheath 444 can be an extrusion that is placed over thehypotube 400, the tubes 440, and the braid or coil 442. This extrusionis subsequently covered by a heat shrink tubing, with the extrusionreflowing and connected to the hypotube 400, the tubes 440, and thebraid or coil 442. In areas of deflection, a softer outer sheath 444 isprovided. The lower durometer of the polymer formed at the deflectionareas allows for easier deflection when a pulling force is applied tothe tension cable (not shown). Optionally, a hydrophilic coating can beapplied to the outer sheath 444. The outer sheath 444 can be a Polyetherblock amide (PEBAX) or other polymer, with a distal flexible portion ofthe outer sheath 444, and so the the intravascular device deliverysystem. The braid 442 and/or outer sheath 444, whether individually orcollectively, aid with keeping the mechanical interlock 410 aligned fordesired torque transmission, as well as a certain amount of pull or pushforce. In other configurations, only one of the braid 442 and outersheath 444 can be included in the hypotube 400.

Turning to another embodiment of the presently described invention, insome circumstances the intravascular device delivery system includes adistal portion with selectable stiffness to aid with steering andpositioning the flexible elongated member, such as an elongated membersimilar to the elongated member 102 in FIG. 1. Selectable stiffnessaids, for instance, in positioning an intravascular device within aparticular anatomical structure or traversing the tortuous anatomy. Byadjusting or varying a distance between two different curves formed bythe intravascular device delivery system, enhanced steerability isprovided. For instance, the selectably stiffened catheter can have avariable stiffness length between a first curve adjacent the septum, forinstance, and a second curve the catheter makes to turn towards anotheranatomical structure within the heart, such as the Mitral annulus.

FIGS. 11 and 12 illustrate a portion of an intravascular device deliverysystem 500 having a catheter body 570 with at least one lumen 572through which a tension or steering cable (not shown) is connected orloops around a portion of an end ring (not shown) attached to a flexiblehypotube 514, similar to that illustrated in FIG. 7. The structure ofthe catheter body 570 is similar to the structure of catheter body 370described herein and so the description of catheter body 370 isapplicable to the catheter body 570.

The proximal ends of the tension cable are attached to a handle, such ashandle 108 (FIG. 1), to allow the flexible hypotube 514 to deflect whentension force is applied to the tension cable extending through the atleast one lumen 572 formed from tubes supported by the hypotube 514,similar to tubes 440, or from sacrificial mandrels that have beenremoved from the catheter during manufacture. The at least one lumen 572is illustrated as being positioned at each bending axis BA₁ and BA₂ ofthe catheter body 570, with a lumen on opposite sides of the bendingaxis BA₁ and BA₂. While two bending axes BA₁ and BA₂ are illustrated, itwould be understood that a greater or lesser number of bending axescould be provided.

The catheter body 570 includes a first region 580 and a second region582, each with enhanced flexibility because of, respectively, aflexibility pattern 584 and 586. Inclusion of the flexibility patterns584 and 586 provides different degrees of stiffness to those particularregions 580 and 582 compared with a third region 588 that is formedeither without any cut pattern, as illustrated in FIG. 11, or with aflexibility pattern that results in a stiffer area than the first region580 or the second region 582. The flexibility pattern 584 and 586 can bethose illustrated and described in FIGS. 4A, 4B, 8, and 9, or otherpatterns of cuts, islands, and other structures that provide differentstiffness to the catheter body 570. The flexibility pattern 584 and 586precisely define bending locations and directions, such as allowing thecatheter body 570 to bend in two different planes that are perpendicularor transverse to each other, while also defining a distance between thefirst region 580 and the second region 582, i.e., a length of the thirdregion 588 that can range from about 0 cm to about 5 cm.

Disposed within the catheter body 570 are lumens or channels 590 thatreceive stiffening members 592. The lumens or channels 590 can be formedfrom tubes 540 disposed on an exterior of the hypotube 514 or bysacrificial mandrels, which can be removed after forming the catheterbody 570. Those tubes 540, like the tubes 440 in FIG. 10, are coveredwith a braid or coil 542 and optional an outer sheath 544 in a similarmanner to the catheter body 370. FIG. 12 illustrates the outer sheath544 reflown and connected to the hypotube 514, the tubes 540, and thebraid or coil 542.

The stiffening members 592 are elongated and movable within the lumens590. In one position, illustrated in FIG. 13A, the stiffening members592 at least partly overlap with the flexibility pattern 586, while inanother position the stiffening members 592 are retracted from andseparated from the flexibility pattern 586, as illustrated in FIG. 13B.When overlapping the flexibility pattern 586, the stiffness ofstiffening member 592 limits bending at the second region 582. To limitbending, an elongate shaft member 594 of the stiffening member 592 has astiffness greater than the stiffness of the second region 582. Forinstance, the elongate shaft member 594 can be fabricated from ahardened metal or alloy, such as steel, or any other stiff material,such as fiber reinforced polymers, ceramics, glass organic or inorganicmaterials, or composites.

By pulling an actuating member 596 proximally, such as with the handle108 (FIG. 1), the stiffening members 592 is withdrawn from alignmentwith the flexibility pattern 586 and they will be uncovered. The secondregion 584 can then bend or deflect when force is applied to the tensionor steering cables 574. In contrast, when the actuating member 596 isadvanced distally within the lumen 590, the elongate shaft member 594again overlaps with the flexibility pattern 586 and the stiffness of thesecond region 582 is increased.

The actuating member 596 can include a flexible pull member 598, such asa pull cable, flexible rod, etc, and a compression member 600 disposedaround the flexible pull member 598. The flexible pull member 598 hassufficient strength in tension to move the elongate shaft member 594proximally, while the compression member 600, such as a compressioncoil, flexible metallic or polymeric tube, or other structure, whichprovides sufficient rigidity or column strength to transfer a forceapplied to the elongate shaft member 594 in a distal direction toadvance the elongate shaft member 594 within the lumen 590.

The articles “a,” “an,” and “the” are intended to mean that there areone or more of the elements in the preceding descriptions. The terms“comprising,” “including,” and “having” are intended to be inclusive andmean that there may be additional elements other than the listedelements. Additionally, it should be understood that references to “oneembodiment” or “an embodiment” of the present disclosure are notintended to be interpreted as excluding the existence of additionalembodiments that also incorporate the recited features. Numbers,percentages, ratios, or other values stated herein are intended toinclude that value, and also other values that are “about” or“approximately” the stated value, as would be appreciated by one ofordinary skill in the art encompassed by embodiments of the presentdisclosure. A stated value should therefore be interpreted broadlyenough to encompass values that are at least close enough to the statedvalue to perform a desired function or achieve a desired result. Thestated values include at least the variation to be expected in asuitable manufacturing or production process, and may include valuesthat are within 5%, within 1%, within 0.1%, or within 0.01% of a statedvalue.

A person having ordinary skill in the art should realize in view of thepresent disclosure that equivalent constructions do not depart from thespirit and scope of the present disclosure, and that various changes,substitutions, and alterations may be made to embodiments disclosedherein without departing from the spirit and scope of the presentdisclosure. Equivalent constructions, including functional“means-plus-function” clauses are intended to cover the structuresdescribed herein as performing the recited function, including bothstructural equivalents that operate in the same manner, and equivalentstructures that provide the same function. It is the express intentionof the applicant not to invoke means-plus-function or other functionalclaiming for any claim except for those in which the words ‘means for’appear together with an associated function. Each addition, deletion,and modification to the embodiments that falls within the meaning andscope of the claims is to be embraced by the claims.

The terms “approximately,” “about,” and “substantially” as used hereinrepresent an amount close to the stated amount that still performs adesired function or achieves a desired result. For example, the terms“approximately,” “about,” and “substantially” may refer to an amountthat is within less than 5% of, within less than 1% of, within less than0.1% of, and within less than 0.01% of a stated amount. Further, itshould be understood that any directions or reference frames in thepreceding description are merely relative directions or movements. Forexample, any references to “up” and “down” or “above” or “below” aremerely descriptive of the relative position or movement of the relatedelements.

The present disclosure may be embodied in other specific forms withoutdeparting from its spirit or characteristics. The described embodimentsare to be considered as illustrative and not restrictive. The scope ofthe disclosure is, therefore, indicated by the appended claims ratherthan by the foregoing description. Changes that come within the meaningand range of equivalency of the claims are to be embraced within theirscope.

What is claimed is:
 1. A method for positioning an end of anintravascular device delivery system, the method comprising: steering asteerable catheter in a first plane, the steerable catheter beingpositioned radially inside a flexible hypotube; bending the flexiblehypotube in the first plane to create a first bend in the flexiblehypotube; advancing the steerable catheter distally relative to theflexible hypotube and distal of a distal end of the flexible hypotube;steering the steerable catheter in a second plane; and positioning adistal end of the steerable catheter at a target location.
 2. The methodof claim 1, wherein the first plane and second plane are non-coplanar.3. The method of claim 1, wherein bending the flexible hypotube includespreferentially bending the flexible hypotube in a direction within thefirst plane.
 4. The method of claim 3, wherein preferentially bendingthe flexible hypotube in a direction includes expanding one or more slitcuts in a bend region of the flexible hypotube.
 5. The method of claim1, wherein advancing the steerable catheter further comprises moving afirst tab of the steerable catheter within a first slot of the flexiblehypotube.
 6. The method of claim 1, further comprising varying aposition of a stiffening member disposed within a lumen associated withthe steering catheter to adjust a stiffness of the steering catheter. 7.The method of claim 1, wherein the steering catheter comprises at leastone island cut and at least one slit cut for a flexibility pattern,wherein varying the position of the stiffening member comprises slidablydisposing the stiffening member within the lumen between a firstposition at least partially overlapping the flexibility pattern and asecond position spaced from the flexibility pattern.
 8. A method forpositioning an end of an intravascular device delivery system, themethod comprising: steering a steerable catheter of an elongated memberin a first plane, the steerable catheter being positioned radiallyinside a flexible hypotube, the flexible hypotube sheath beingpositioned radially outside and circumferentially about the steerablecatheter and coaxial with the steerable catheter, the flexible hypotubesheath including at least one island cut and at least one slit cut todirect flexibility of the flexible hypotube, the flexible hypotube andthe steerable catheter being rotationally fixed to one another at afirst key assembly; bending the flexible hypotube in the first plane tocreate a first bend in the flexible hypotube; advancing the steerablecatheter distally relative to the flexible hypotube and distal of adistal end of the flexible hypotube; steering the steerable catheter ina second plane; and positioning a distal end of the steerable catheterat a target location.
 9. The method of claim 8, wherein the first planeand second plane are non-coplanar.
 10. The method of claim 8, whereinbending the flexible hypotube includes preferentially bending theflexible hypotube in a direction within the first plane.
 11. The methodof claim 10, wherein preferentially bending the flexible hypotube in adirection includes expanding one or more slit cuts in a bend region ofthe flexible hypotube.
 12. The method of claim 8, wherein advancing thesteerable catheter further comprises moving a first key memberassociated with one of the steerable catheter or the flexible hypotubewithin a first slot of the other of the steerable catheter or theflexible hypotube.
 13. The method of claim 12, wherein the first slothas a first slot length in a range of 2.0 centimeters and 7.0centimeters.
 14. The method of claim 12, further comprises moving asecond key member associated with one of the steerable catheter and theflexible hypotube within a second slot of the other of the steerablecatheter or the flexible hypotube, the first slot and the second slothaving equivalent lengths.
 15. A method for positioning an end of anintravascular device delivery system, the method comprising: steering asteerable catheter in a first plane, the steerable catheter beingpositioned radially inside a flexible hypotube, the flexible hypotubesheath including at least one island cut and at least one slit cut todirect flexibility of the flexible hypotube; bending the flexiblehypotube in the first plane to create a first bend in the flexiblehypotube; advancing the steerable catheter distally relative to theflexible hypotube and distal of a distal end of the flexible hypotube;steering the steerable catheter in a second plane; and positioning adistal end of the steerable catheter at a target location.
 16. Themethod of claim 15, wherein steering the steerable catheter comprisesmanipulating one or more controls of a handle to move the steerablecatheter longitudinally relative to the flexible hypotube.
 17. Themethod of claim 15, wherein advancing the steerable catheter distallyrelative to the flexible hypotube and distal of a distal end of theflexible hypotube further comprises longitudinally moving the steerablecatheter at least 2 centimeters.
 18. The method of claim 15, wherein thesecond plane is perpendicular to the first plane.
 19. The method ofclaim 15, wherein positioning the distal end of the steerable catheterat the target location further comprises positioning an intravasculardevice positioned at the distal end within a heart of a patient.
 20. Themethod of claim 19, wherein the intravascular device is a filter, ascaffold, a stent, a body tissue repair device, or an implantable heartvalve.